Hydraulic cylinder and expansible piston arrangement



Nov. 23, 1954 E. w. FREEMAN 2,695,008 HYDRAULIC CYLINDER AND EXPANSIBLE PISTON ARRANGEMENT Filed April 17, 1950 I N V EN TOR. Ed /ya, h/ Freeman HTTOR/VEY United States Patent HYDRAULIC CYLINDER AND EXPANSIBLE PISTON ARRANGENEENT Edgar W. Freeman, Yankton, S. Dak. Application April 17, 1950, Serial No. 156,443 1 Claim. (Cl. 121-38) My invention relates to a hydraulic cylinder.

An object of my invention is to provide a hydraulic cylinder and piston arrangement possessing certain features whereby the piston cannot be forced out of the cylinder, and to provide further means for efliciently packing the slidable arrangement in the cylinder, and to provide further other objects as will be apparent.

With these and other objects in View, my invention consists in the construction, arrangement, and combination of the various parts of my device, whereby the objects contemplated are attained, as hereinafter more fully set forth, pointed out in my claim, and illustrated in the accompanying drawings, in which:

Figure 1 is a sectional view taken substantially longitudinally of the cylinder;

Figure 2 is a sectional view of Figure 1 taken substantially along the lines 2-2 thereof; and

Figure 3 is a sectional view taken along the lines 3-3 of Figure 1.

I have used the character to designate the hollow cylinder of my arrangement, which cylinder merges with the expanded portion 11 which is threaded at 12 and 13. Threadably engaged with the threads 12 is an annular packing member 14 which can be tightened by means of the depressions 15 in combination with a suitable wrench, and threadably engaged with the threads 13 is a further limiting member 16.

The piston of the arrangement includes the lengthened cylindrical portion 17, which terminates in the expanded end 18 which slidably engages the inner bore of the member 10, the member 18 including the inclined oil passageway 19. Welded at 20 to the tube 10 is the rear plug 21, and the character 22 designates openings whereby the cylinder can be pivotally attached or otherwise attached as desired, it being understood that the arrangement can be employed for any desired purpose using hydraulic principles.

Attached to the cylinder 10 at 23 is an entrance opening 24 which communicates to the pressure oil source. The member 17 extends into the integral flattened portion 25 which includes an opening 26, for attachment to any of the devices to be operated by the piston.

The arrangement is assembled with the retaining member 16 being screwed into its threads from the open end of the member 11, and thence several annular packing rings 27 are compressed by means of the member 14, the several packing washers thereby providing a tight seal through which the member 17 can pass. The members 27 as shown are preferably in a slightly dished form cross sectionally.

It will now be noted that the piston member 17 cannot be forced out of the cylinder due to the fact that the member 18 will abut against the number 16. The provision of the members 16 and 14 also provides an eflicient packing arrangement in combination therewith. The passageway 19 permits the oil pressure to pass behind the member 18 at the beginning of the stroke, this slot being inclined as shown for the purpose of preventing scoring or abrading of the inner walls of the member 10, since due to its angularity which covers a greater Width than the thickness of the slot itself, there will be no tendency for a straight line abrading action.

It should be noted that the fluid which is at the left of piston 18, as the piston travels towards the left, will pass to the right of the piston through the groove 19.

It will now be seen that I have provided the various advantages set forth in the objects of my invention with various other advantages being readily apparent.

Some changes may be made in the construction and arrangement of the parts of my invention without departing from the real spirit and purpose of my invention, and it is my intention to cover by my claim any modified forms of structure or use of mechanical equivalents which may be reasonably included within their scope.

I claim as my invention:

A hydraulic unit comprising a cylinder, a piston slidably received within said cylinder, a rod portion attached to said piston, said cylinder including packing means for receiving said rod portion, said piston having a passageway positioned on and completely across the periphery thereof, said passageway being inclined to prevent scoring of the cylinder walls, said cylinder including a head end, a fluid inlet member communicating with said cylinder at a position between the rod portion end of the cylinder and said piston when said piston is fully retracted towards the head end.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,530,505 Levedahl Mar. 24, 1925 1,681,444 Stevens Aug. 21, 1928 1,910,240 Casper May 23, 1933 2,204,365 Klemm June 11, 1940 2,288,511 Bratz et a1 June 30, 1942 2,312,579 OBrien Mar. 2, 1943 

